shell: add fs.meta.cat to see file meta data content

related to https://github.com/chrislusf/seaweedfs/issues/1163

weed/shell/command_fs_meta_cat.go

@@ -0,0 +1,75 @@
+package shell
+
+import (
+	"context"
+	"fmt"
+	"io"
+
+	"github.com/golang/protobuf/jsonpb"
+
+	"github.com/chrislusf/seaweedfs/weed/filer2"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+)
+
+func init() {
+	Commands = append(Commands, &commandFsMetaCat{})
+}
+
+type commandFsMetaCat struct {
+}
+
+func (c *commandFsMetaCat) Name() string {
+	return "fs.meta.cat"
+}
+
+func (c *commandFsMetaCat) Help() string {
+	return `print out the meta data content for a file or directory
+
+	fs.meta.cat /dir/
+	fs.meta.cat /dir/file_name
+	fs.meta.cat http://<filer_server>:<port>/dir/
+	fs.meta.cat http://<filer_server>:<port>/dir/file_name
+`
+}
+
+func (c *commandFsMetaCat) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
+
+	input := findInputDirectory(args)
+
+	filerServer, filerPort, path, err := commandEnv.parseUrl(input)
+	if err != nil {
+		return err
+	}
+
+	ctx := context.Background()
+
+	dir, name := filer2.FullPath(path).DirAndName()
+
+	return commandEnv.withFilerClient(ctx, filerServer, filerPort, func(client filer_pb.SeaweedFilerClient) error {
+
+		request := &filer_pb.LookupDirectoryEntryRequest{
+			Name:      name,
+			Directory: dir,
+		}
+		respLookupEntry, err := client.LookupDirectoryEntry(ctx, request)
+		if err != nil {
+			return err
+		}
+
+		m := jsonpb.Marshaler{
+			EmitDefaults: true,
+			Indent:       "  ",
+		}
+
+		text, marshalErr := m.MarshalToString(respLookupEntry.Entry)
+		if marshalErr != nil {
+			return fmt.Errorf("marshal meta: %v", marshalErr)
+		}
+
+		fmt.Fprintf(writer, "%s\n", text)
+
+		return nil
+
+	})
+
+}